Blending Modes

Pixels in layers will blend together for the final image. Blending modes control how the different pixel colors interact with each other. When blending, the "base" layer is the layer on the bottom and the "over" layer is on top.

Alpha blending modes

Normal blending modes utilize the alpha channel only. Unless otherwise specified, the other modes will do Normal blending in addition to their other blending modes.

Normal

This is basic alpha blending. The value of the alpha channel determines how much of the over color mixes with the base color. An alpha value of 255 (100%) will keep the over color, a value of 0 (0%) will keep the base color.

Dissolve

Instead of blending 2 colors, Dissolve will pick just the over or base color and the alpha channel determines the likelihood of a given color being chosen.

Keyed

This treats the current background (or fill) color as transparent, similar to Keyed selection mode. This allows you to lift text out of screenshots without taking the background with it.

Light

These modes deal with how light is applied between the layers. All operations apply to each red, green, and blue channel independently.

Dodge

Dodging has its origin in film photography where light is blocked from developing the film. This results in a darker, higher-contrast version of the base layer.

Burn

Burning is the inverse of dodging where extra light is added. This results in a lighter, lower-contrast version of the base layer.

Multiply

Multiplies the brightness of each channel where black is 0 and white is 1. This results in a proportionally darker image. Multiplying with white results in no change.

Screen

Screen is sort of the inverse of Multiply. This results in a proportionally lighter image. Screening with black results in no change.

Overlay

Combines Multiply and Screen to adjust midtones. White acts like Screen, black acts like Multiply, and 50% gray does nothing.

Hard Light

This is the inverse of Overlay, using the values of the over layer rather than the base layer.

Soft Light

This is a softer version of Overlay that allows you to adjust brightness and contrast in a smoother way.

Hard Mix

This turns each channel into its most extreme version, all or nothing. The resulting color will be black, white, red, yellow, green, cyan, blue, or magenta.

Arithmetic

These modes perform simple mathematical operations on each channel.

Add

This adds the two layers together. If the colors exceed 100%, the result is white.

Subtract

This subtracts the over layer from the base layer. If the colors reach 0%, the result is black.

Divide

Divides the base layer by the over layer, producing a brighter image. Pure white does nothing and black turns to white.

Difference

Takes the absolute value of the difference between the layers. Black does nothing, white inverts the colors, and colors in between perform a solarize effect.

Exclusion

Similar to Difference but 50% gray turns the image 50% gray.

Lighten

This chooses the brighter color of each channel.

Darken

This chooses the darker color of each channel.

Lighter Color

This chooses the brighter color across all channels.

Darker color

This chooses the darker color across all channels.

Bitwise Math

These modes perform bitwise math on each channel. Each color is treated as a set of binary digits (bits) and each bit has a logical operation applied to it.

AND

Chooses bits in common between both layers. This preserves black areas. A practical use for this is to highlight using a primary or secondary color such as yellow for black text on a white background; the background will be highlighted while the text remains clear.

OR

Chooses bits that exist in either layer. This preserves white areas.

XOR

Chooses bits from one layer or the other but not both. Another way to look at this is that XOR inverts each bit on the base layer if set on the over layer. XORing with white inverts the color. The XOR operation is invertible so creating a second layer with XOR blending mode and applying the same operation will undo the previous one. (This was the technique used for selection rectangles in older versions of Windows when alpha blending was too slow to be practical, as this effect could be trivially done in hardware.)

XNOR

Performs the inverse of the XOR operation. Useful when you want a XOR-like effect but the background is white.

Over IMP Base

Performs a logical implication on each bit. (If P implies Q, the statement is true in all cases except when P is true and Q is false.) This selects the bits from the base layer regardless of the over layer unless the bit in the base layer is 0, then it selects the bit from the over layer.

Base IMP Over

This is the same as Over IMP Base but with the layers reversed.

RGB

These blending modes operate in the RGB color space. They are primarily used in the Compose/Decompose layer operations to enable independent manipulation of the color channels.

Red

Selects the red values from the over layer and the green/blue values from the base layer.

Green

Selects the green values from the over layer and the red/blue values from the base layer.

Blue

Selects the blue values from the over layer and the red/green values from the base layer.

Average

Selects the average value from all 3 channels. This is equivalent to using Normal blending mode with 50% opacity.

HSL

These blending modes use the hue/saturation/lightness color space.

Hue

Selects the hue from the over layer. This allows you to colorize the base layer.

Saturation

Selects the saturation from the over layer. This allows you to adjust saturation without affecting the color.

Color

Selects the hue and saturation from the over layer and keeps the lightness from the base layer. This allows a more intense recoloring effect.

Lightness

Selects the lightness from the over layer and keeps the hue and saturation from the base. This is the inverse of the Color blending mode.

Roll Hue

Allows you to shift the hue by using the lightness of the over layer. Black and white have no effect while 50% gray will shift the hue by 180 degrees (50%).